Mechanism for grinding and polishing gear-wheels



8 J GARDNER, s1. & J. A. GOBURN. F N P I GEAR WHEELS.

Patented Feb. 9, 1892.

ITNESS ES.

NVEN l f@w THE NORRIS I'ITERS ED FHOTO-L|THO., WASHINGTON, D. C4

UNITED STATES PATENT OFFICE.

JOHN GARDNER, SR, AND JOHN A. COBURN, OF CANTON, OHIO.

MECHANISM FOR GRINDING AND POLISHING GEAR-WHEELS.

SPECIFICATION forming part of Letters Patent No. 468,400, dated February9, 1892.

Application filed June 5, 1890. Serial No. 354,397. (No modeld To allwhom it may concern.-

Be it known that We, JOHN GARDNER, Sn, and JOHN A. COBURN, citizens ofthe United States, and residents of Canton, county of Stark, State ofOhio, have invented a new and useful Improvement in Mechanism forGrinding and Polishing Gear-\Vheels, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings, making part of this specification.

This invention relates to an improved In echanism to automatically grindand polish the teeth of gear-wheels, more especially for gri uding teethon watch and clock wheels or other wheels where a high degree ofaccuracy is required; and itconsists in providingagrindinglap havingabout its periphery a helical form of worm having a pitch line andradials to correspond with the pitch and radial lines of the teeth to beground or polished.

\Vith these ends in view this invention consists in certain features ofconstruction and combination of parts, as will be hereinafter described,and pointed out in the claim.

Figure 1 of the accompanying drawings is a plan view of a lap-wheel,illustrating our in vention. Fig. 2 is an end view or elevation of atoothed wheel and a transverse section of the peripheral worm and afragment of the lap, showing the short radials in engagement on bothsides of the pitch lines. Fig. 3 is a similar view showing the worm andteeth engaged on the pitch lines; Fig. 4, a similar View showing theworm and teeth disengaged. Fig. 5 is an edge or face view of the lap.

Similar letters of reference indicate corresponding parts in all of thefigures of the drawings.

A represents a lap or grinding wheel having about its periphery anannular tangential tooth or worm B, having radial and pitch lines tocorrespond with similar lines of the teeth to be ground or polished.

The lap and worm may be made of any suitable material, preferably oftin, or, when preferred, the continuity of the worm portion B of the lapmay be interrupted or divided into spiral ribs of such length as may bebest adapted to the .work to be done, as shown at aand b, Fig.1. Theshoulders formed thereby will carry the grinding 'powdersuch asemery-across the face of the tooth being ground.

The utility of this invention will be fully appreciated by thosefamiliar with the art of making such gear-wheels, for however perfeetthe cutting machinery the teeth of such wheels are liable to have moreor less of imperfectionson their working faces. By the use of thisinvention these imperfections may be removed, the teeth ground to theirproper working lines with a degree of accuracy not accomplished by theconsecutive methods now in use, and their relative accuracy to the axispreserved.

Having thus fully described the nature and object of our invention, whatwe claim as new, and desire to secure by Letters Patent, is-

A grinding or polishing lap having on its periphery an annular spiralworm, portions of which are cut away to form shoulders.

In testimony whereof we have hereunto set our hands this 26th day ofMay, A. D. 1890.

JOHN'GARDNER, SR. JOHN A. COBURN. Witnesses:

CHAS. R. MILLER, \V. K. MILLER.

